The present invention pertains to a crop harvesting apparatus. More particularly, the present invention pertains to an automated apparatus for the mechanized harvesting of crops and, in particular, tree-borne crops such as fruit, nuts and the like.
At the present time, many tree-borne crops such as fruit and nuts are harvested by hand. While attempts have been made to perfect mechanized crop harvesting apparatus, these have not been wholly successful heretofore. Many such apparatus have caused damage to the crop-bearing plant or to the crop itself. Likewise, many prior art apparatus have been unable to pick crops with great enough efficiency or speed to be economically successful. Fruit trees must not be damaged to any extent during the harvesting of fruit, or the trees will yield less fruit in subsequent crops. Thus, mechanized fruit harvesting apparatus must be capable of removing the fruit from the tree without removing an excessive quantity of leaves and branches. Removal of even a small quantity of leaves and branches is undesirable, even though that may not cause appreciable damage to the trees, since such leaves and branches must be removed from among the fruit before marketing. Likewise, the fruit itself must not be damaged to any great extent if it is to be marketable. While fruit which is intended for processing need not be in perfect condition, still it cannot be damaged excessively or it will be unsuited even for processing. Citrus fruit of the Valencia variety stays on the tree for over a year before it is ripe. As a consequence, at the time the Valencia fruit is harvested, the fruit tree is bearing unripened or green fruit of the new crop and ripened fruit of the crop to be harvested. An automatic crop harvesting apparatus must be capable of picking the ripe Valencia fruit while leaving the unripened fruit.
I previously have proposed crop harvesting apparatus which have provided improved harvesting over earlier forms of mechanized crop harvesters. Thus, U.S. Pat. No. 3,646,741 discloses a crop harvesting apparatus which includes an elongated hollow cylindrical shell with a plurality of crop-entry openings for the entry of the crops. Each crop-entry opening terminates in a crop-severing edge. The shell is thrust lengthwise among the crops and rotated, removing crops from the plant. Each crop-entry opening is provided with a closure or door which prevents mature, ripened fruit from leaving via the crop-entry opening, while permitting immature green fruit, leaves, and branches to pass from the shell without being severed from the plant. While this apparatus performs better than previously available mechanized crop harvesting devices, still shortcomings exist. The closures or doors on the crop-entry openings slow operation of the apparatus. While the apparatus does not remove so many leaves from the trees as to cause appreciable damage to the trees, still some leaves are removed and mixed with the harvested crops. This necessitates separating these leaves from the crops before marketing of the crops.
Likewise, my U.S. Pat. No. 3,992,861 discloses a crop harvesting apparatus in which a plurality of crop-severing devices are mounted on rotatable drive shafts. The crop-severing devices can take any of several forms. Thus, for example, they might be arcuate members including a crop engaging portion and a crop passage portion terminating in a crop-severing edge. Alternatively, the crop severing devices can be one or more crop-severing rods mounted onto a rotatable drive shaft and they might include a set of foliage-lifting rods which rotate more slowly than do the crop-severing rods. The crop-severing devices are thrust into the crop bearing foliage with the direction of thrust being transverse the longitudinal axes of the crop-severing rods. Again, while improved performance is achieved, still this crop harvesting apparatus removes an undesirable amount of foliage and does not remove as high a percentage of mature fruit as is desirable.
Likewise, my later crop harvesting apparatus, disclosed in my United States Patent Application Ser. No. 508,903, filed Sept. 24, 1974 now abandoned, utilizes rotatable rods which are thrust end first among the crop bearing foliage with the direction of thrust being parallel with the longitudinal axes of the crop-severing rods. In one form of this apparatus the rods are felxible so that, as they rotate, they achieve an orbital path. Experience has shown, however, that even these rods do not remove as high a percentage of the mature fruit as is desirable.